<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=1200, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <ul id="Books">
        <li>Java</li>
        <li>Python</li>
        <li>JavaScript</li>
        <li>Android</li>
    </ul>
    <script>
        const books = document.querySelector("#Books")
        /*
        books.setAttribute("style","border: 1px solid red")

        books.style.color = 'red'  // color: red;
        books.style.backgroundColor = "blue"  // background-color: blue;
        books.style.borderStyle = "dotted"  // border-style: dotted;
        books.style.cssFloat = "right"    // float: right;
        */

        books.setAttribute("style","border: 1px solid red")
        console.log(books.style.border)  // 1px solid red
    </script>

</body>
</html>